Electric heater



Oct. 21, 1930.

1.. MCKINNEY ELECTRIC HEATER Filed May 9, 1928 Hal x74) 777C fag 15mm.

' ATTORNEYS.

"18 of the element supports.

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This invention is designed to improve electric heaters. This is. accomplished by improving the method of Sn element. Features and details of the invention appear from-the specification and aims.

' A preferred embodiment of the heater and method is illustrated in the accompanying g wingasfollows; 1 shows a centralsection of an electric heater, this being in the specific formshown .a waflle iron. Fig. 2 a bottom view of the hot plate.

'Fig. 3 an enlarged perspective view of one Fi 4a mold sho the manner of securing e supports to the ot plate.

1 marks the heater frame, 2 a closure plate formed on the frame, and 3 a hot plate 80 mounted on the frame above the closure plate. A series of insulating electric element supports 4 are, mounted on the plate 3. These supports have openings 5 through them and are, as shown, circumferentially around the.plate andthe heating element 6 is threadedthro htheo 5,theendsbein eterminals ach support isprovided with sockets 8 I from one surface of the support so and these sockets. have-vent openings 9 ex-.

tending through the opposite face of'the supw tl 1n securing'the supports to the plate the ollowing method is employed: 10 represents cope. mold cavity 12 is formed in thesand of the drag of the mold and'cope, this mold cavity being suitable to receive the metal formmg the hot plate. At the same time the pattern has prints corresponding in shape to the su ports 4 and form theprint cavities 18 exten from the mold cavity. The sup ports 4 are' lacedin these print cavities in the mold an the metal is then poured fillin the mold as shown in Fig. 4. As the meta 1 is poured it flows into the sockets .8 and the cooling of the metal thus secures the supports to the plate. The sockets extending in a perpendicular direction to the plate facilitate 60 this although this is not essential for all and this intimate relation is also true with relation to heat transfer by we of the scourthe dra of an ordinary mold flask and 11 the forms of supports. The metal flowing into these cavities, or sockets, makes a nice fit with pporting a heating,

the sockets without exerting undue strain 'on any localized point. Consequently the insulating supports which are ordinarily porcelain and fragile will stand 'a great deal more pressure, or shock, than with ordinary means of securing such supports where such strains are from necessity ocalized on points of contact. The engagm surfaces conform exactl to the surfaces 6 the supports even though t ere ma be quite a variation and thus there is an intimate contact between the supports and the plate througlhwhich there may be heat transfer from t e element to the plate ing plugs, or projections 14. e apparatus, therefore, is stro r than the ordinary means of support, t e forming of the mold cavities takes no longer than it would with,- out the prints for the insulating supports and the placing of the insulating supports reuires less time than any ordinary operation t at would secure them to the plate and there is an absence of localized contact with the insulatinaimaterial so that there is less liability of bre age and greater heat transfer than withthe common methods of se r g such devices.

What I cIaim as new is:

1. In an electric heater, the combination of an electric heating element; insulati supports forthe element a plate heated by the element, said element being exposed between the supports and in radiating relationto the plate; and means securing the support to the plate, the engaging surface of the p ate with the support being a cast of the opposing engaging surface of the support w ereby there is a continuous heat exchanging contact ing sockets; and a plate of metal the supports, said element being exposed between said supports and in radiating relation to said plate. v

3. In an electric heater, the combination of an electric heating element; insulating supports for said element, said support havam 111- tegral projections extending into the soc ets the walls of the sockets extending around and engaging the walls of the projections to secure the supportfto the plate, the heating element being exposed between its supports and in radiatmg relation to the late.

4. In an electric heater, the com ination of electric heating element insulating supports for said element, eac of said sufpports having an element receiving openin or the heating element and a securing soc et; and

a plate of metal having integral projections "extending into the sockets of the supports, the

walls of the sockets extending around and engaging the projections for securing the supports on the plates, said element being exposed between'its supports and in radiatrelation to the plate.

in testimony whereof I have hereunto set my hand. a

LON MCKINNEY. 

